Refrigerating apparatus



July 28, 1931. F. w. ANDR EWS 1,815,952

REFRIGERATING APPARATUS Filed April 2a. 1927 Patented July 28, 1931 FRANK w. ANDREWS, OF DAYTON,

OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

FRIGIDAIBE CORPORATION,.A CORPORATION OF DELAWARE BEFRIGERATING APPARATUS 'Application filed April as,

- i This invention relates to refrigerating apparatus of the compression type.

One of the objects of the invention is to charge refrigerant into a compression system, particularly under service conditions, in a simpler, and more reliable and more expeditious manner than has been done heretofore.

It is also one of the objects to construct the apparatus constituting a refrigerating system in such a' manner as to facilitate the charging of refrigerant.

Still another object is to construct the apparatus so as to facilitate determination of the exhausting of'the reserve supply of refrigerant.

Further objects and advantages of the v present invention will beapparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of embodiment of the present invention is clearly shown.

In the drawings: Fig. 1 is a diagrammatic illustration. of a refrigerating system showing a method of charging refrigerant.

Fig. 2 is a section thru-a portion of the apparatus shown in Fig. 1.

The refrigerating system shown in the drawings comprises a'compressor 2O driven by a motor 21 and connected to a condenser 22 which discharges into a receiver or reservoir 23 for liquid refrigerant, the bottom of which is connected thru a conduit 24 with an evaporator 25. The evaporator is connected to the intake side of the compressor thru a conduit 26. The evaporator is of the flooded type, having a valve operated by a float 27 for maintainin liquid refrigerant supplied thru the con uit 24 at constant level. The compressor is operated in response to refrigerating demand thru. the agency of any suitable automatic switch 30, which may be actuated by a pressure-responsive device 31 connected to the conduit 26. The apparatus thus far described is conventional and its particular construction forms no part of the present invention.

The system is designed to operate with a constant quantity of liquid refrigerant in the 1 suitable supply Will 1927. Serial No. 187,355. evaporator indicated by the lever 28) and with a certain reserve supply of liquld refrigerant in the reservoir 23, indicated for example, by the level 29. Due to various causes, for example leaks, the system may not contain enuf, refrigerant. The condition of an insufficient quantity of refrigerant may be indicated in various ways, for example, by frequent starting and stopping, or by a hissing sound at the float valve, or by failure to refrigerate. It will be understood that the pressure within the condenser and receiver is high (for example it may be pounds per square inch gauge.) and therefore as long as there is any liquid in the receiver it will be forced into the conduit 24. If suflicient refrigerant has been lost from the system, the liquid level in the evaporator will not be high enuf to close the float valve and all of the liquid in the receiver will flow into the evaporator.

My invention provides means whereby re.- frigerant may be readily charged into the system. The conduit 24 is provided 'with two valves 35 and 36 and has a branch connection 37 containing a valve 38. The connection 37 is adapted to be connected to any of liquid refrigerant 40. Preferably this 1s a container such as a steel bottle, inverted as shown in Fig. 1, and containing a quantity of liquid refrigerant 41 and a quantity of gaseous refrigerant 42. It be understood that the refrigerant boils at a very low temperature, therefore a bottle containing liquid refrigerant at ordinary room temperature will be at high pressure. Thus at a temperature of 70 F'., the pressure of the gaseous refrigerant may be 35 pounds per square inch.

.Whenit is desired to charge refrigerant into such a system the container 40 is connected to the line 37, the valves 35 and 38 being closed. The compressor is then operated and withdraws gaseous refrigerant from the evaporator and forces it into the receiver. In a given apparatus the compressor will pump gaseous refrigerant at a definite rate. This rate may be, of course, influenced by the temperature and consequently the density of the gas in the evaporator, but it is found that -.f orce into the receiver the desired reservequantity of refrigerant. This is measured,

thruout the range of ordinary operating conditions this rate may be considered constant for'practical-purposes. The compressor is then operated the required length of time to remove from the evaporator, condense and s mply bytiming the operation of the compressor. The refrigerant pumped intothe receiver can not flow back into the evaporator becausejthe valve 35 is closed. The'compressor reduces the pressure within the evaporator and conduit 24, to some value below the pressure existin in the container 40, for example" to 10 ,poun s per square inch, gau e. v The valves 36 and38 are now opened U Re igerant flows from the container thru the conduit 24 into the evaporator until it'raises .the float and closes" the entrance to the evaporator. When this occurs no more refrigerant can enter the system from the container 40, the evaporator float valve will permit it.

contains its normal quantity of refrigerant, and thedesired reserve has been accumulated in the reservoir 23. The valve 38 can then be closed and the container removed, if desired. When the valve 38 has been closed the valve 35' may be opened and the system operated in its normal manner.

As a modification of the above described,

procedure the valve 38 may be left open while the compressor is running to pump the reserve from the evaporator into the receiver. The 'compressorwill pump at the same-rate as if the valve were closed and the refrigerant can flow into the evaporator as fast as the In Fig. 2 I have shown one form of structural arrangement .of the valves 35, 36 and 38. In this-figure, 24: indicates the portion of the conduit 24: which connects with the bottom of the'receiver. Connected to the pipe 24 by any suitable means such as a nipple 50, is a fitting which includes a housing or casing .51 having a valve chamber 52 and passageways .53, '54 and 55 leading into the valve chamber. A valve stem 56 is threaded into the casing as at 57 and carries a head 58 on which are formed the two valves 35 and 36 indicated diagrammatically in Fig. 1. The valves co-operate with seats 35" and 36. to close the passages 53 and 55 respectively. The passage 54 communicates with a chamber containing a strainer 60 and leading to the conduit 24. The passage 55 is threaded to receive a fitting 61 containing the'shut-ofi valve 38 and the branch connection 37 which receives the conduit 39 connectduring normal operation of the refrigerating system. In this position it is immaterial whether the valve 38 is open or closed, the 1 valve 38 being provided to close the conduit 37 whenever the valve 36 is open. When the stem 56 is in its lower position, it will be seen that the-valve 36 is open. and the valve 35 seated to shut off communication between the receiver and evaporator as well as between the receiver and the container connection 37 Whenever the valve 35 is seated, the valve 38 may be opened to admit refrigerant from the container. I

The above described fitting also provides a simple means for testing the system to ascertain whether there is any liquid in the receiver. Under certain conditions the receiver may be empty notwithstanding the fact that no hissing noise can be heard at the float valve. A test for this condition is as follows:

With the container 40 disconnected, close the shut-oil? valve which is ordinarily provided at the evaporator end of the conduit 24; turn the valve stem 56 until the valve head 58 is in its mid position that is, with valves 35 and 36 both open; open thevalve 38 slightly. If there is liquid present in the receiver liquid will flow from valve 37, but if the receiver is empty, s will emerge, indicating that the reserve is exhausted and that the system needs charging.

While the form of embodiment of the present invention as hereindisclosed, constitutes a referred form it is to be understood that 0t er forms might be adopted, all coming within the $00 e of the claims which follow.

What is claimed is as follows:

1. Refrigerating apparatus comprising an evaporator, a c'ompressor,'a condenser, conduits connecting said evaporator, compres-- sor and condenser in a closed circuit in the order namedfmeans for closing the conduit between the condenser and evaporator, means for closing the entrance to the evaporator in response to the quantity of liquid refrigerant in the evaporator, and means between said two closing means for admitting a supply of liquid refrigerant.

2. Refrigerating apparatus comprising an evaporator, a compresor, a condenser, conduits connecting said evaporator, oompres sor and condenserin a closed circuit in the order named,'means for closing the conduit between the condenser and evaporator, a container for liquid refrigerant, and a connection between a point below the level of liquid in said container and a point between said closing means and the evaporator.

3. Refrigerating apparatus comprising an evaporator, a compressor, a condenser, conduits connecting said evaporator, compressor and condenser in a' closed circuit in the order Inamed, means for closing the entrance to the evaporator in response to the quantity of liquid refrigerant in theevaporator, means for closing the conduit between the condenser and evaporator, a containenfor liquid. refrigerant, and a connection between a, point below the level of liquid in said container 5 and a point between said closing means and the evaporator.

In testimony whereof I hereto aflix my signature. 7

'1" *3 W. REWS. 

